Liquid Effluent
•Organic
pollutants
•Inorganic
pollutants
•Biological
contamination
•Pathogenic
microorganisms
Neighborhoo...
Intracellular parasite that infect vertebrates including
humans.
Belongs to Apicomplexa an obligate parasitic group of
Euk...
The life cycle of this
parasite is complex,
showing both asexual
and sexual stages.
The persistence of
oocysts in environm...
Oocyst can remain viable and infectious in
water for several months at temperatures
ranging from 0 to 30c.
Boiling water c...
Filtration
Methods
Membrane
Filtration
Cartridge
Filtration
Woven Acrylic Polyethersulfone
Chemical
Flocculation
Another m...
 NRC 1983 defines risk evaluation of toxic
characteristics of a chemical product and
conditions of human exposure to this...
 Water distribution were analyzed at different
periods by sampling at least 100L.
 Samples were taken from 8 reservoirs,...
 Highlighted the presence of cryptosporidium
oocysts in the surface and ground water of
the coastal city of Cayes.
 The ...
A risk factor is an
element belonging to an
individual or originating
from an environment
liable to cause an
illness, trau...
Conclusion:
Risk assessment is not a goal but there is an
decision making for risk management of oocyst
hazards and risks ...
Cryptosporidium oocysts in the aquatic environment of Haiti
Cryptosporidium oocysts in the aquatic environment of Haiti
Cryptosporidium oocysts in the aquatic environment of Haiti
Upcoming SlideShare
Loading in …5
×

Cryptosporidium oocysts in the aquatic environment of Haiti

247 views

Published on

Published in: Healthcare, Technology, Business
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
247
On SlideShare
0
From Embeds
0
Number of Embeds
3
Actions
Shares
0
Downloads
4
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Cryptosporidium oocysts in the aquatic environment of Haiti

  1. 1. Liquid Effluent •Organic pollutants •Inorganic pollutants •Biological contamination •Pathogenic microorganisms Neighborhood Pollution •Rainwater •Urban waste water Underground water •Highly polluted effluent discharges •Waste water and runoff water Pollution in aquatic environment Biological pollution oocysts of cryptosporidium detected in surface water of Port-au-Prince which used as an drinking water. Cryptosporidia are responsible for 17.5% of acute diarhreas in infants under 2 aged and 30% of chronic diarrheas in patients infected by HIV
  2. 2. Intracellular parasite that infect vertebrates including humans. Belongs to Apicomplexa an obligate parasitic group of Eukaryotes. Species of cryptospordium parasitize specific host tissues such as stomach, small intestine or trachea. Cryptosporidiosis is a self limiting disease in healthy host but represents a life threatening problem in immunocompromised individuals for which there is no effective method.
  3. 3. The life cycle of this parasite is complex, showing both asexual and sexual stages. The persistence of oocysts in environmental compartment can be influenced by their age and chemical disinfectants. Under natural conditions, fecal matter shelters oocysts from desiccation and increase impermeability of the wall to small molecules, thus reducing their exposure to lethal environmental factors. The resistance of oocysts in a solid matrix such as soil has become a crucial parameter in understanding their transfer to lower layers.
  4. 4. Oocyst can remain viable and infectious in water for several months at temperatures ranging from 0 to 30c. Boiling water can kill cryptosporidium oocysts in less than a minute. Exposure to sunlight had no effect on the viability of cryptosporidium oocysts but UV at 265nm & black light at 365nm lead to a reduction in the no. of viable oocysts. Oocysts resistance
  5. 5. Filtration Methods Membrane Filtration Cartridge Filtration Woven Acrylic Polyethersulfone Chemical Flocculation Another method is elution & its efficiency depends on turbidity of sample, the type of filter & the method chosen. Oocysts trapped by filter are eluted by detergent solutions that break hydrophobic interactions b/w oocysts, sediment particles and filter fibers. Now centrifuge the eluate to improve separation of desired oocysts. Use solutions containing dispersive agents i.e, EDTA increases the average % of cryptosporidium oocysts recovery.
  6. 6.  NRC 1983 defines risk evaluation of toxic characteristics of a chemical product and conditions of human exposure to this product.  Health risk evaluation relies on an epidemiological approach.  Evaluating health risk is based on four steps: Identifying the danger Dose response relationship Estimating exposure Characterizing the risk
  7. 7.  Water distribution were analyzed at different periods by sampling at least 100L.  Samples were taken from 8 reservoirs, 7 points of city drinking water network and 3 public fountains.  The exposed population was divided into 4 categories: 1 • Immunocompetent aged 5 & over low risk of infection. 2 • Immunodepressed aged 5 & over with severe illness linked to HIV. 3 • Immunocompetent under 5 years old high risk of illness. 4 • Immunodepressed under 5 years old leads to high risk of illness. Number of persons contaminated by HIV in Haiti is estimated to be about 400,000 i.e, 5% of the total population. Following equation was used to determine the probability of infection: Pr = 1- exp(-rD) Where: P= probability of infection of an individual exposed to Dose D of oocysts r= the probability of survival of oocysts in drinking water ingested by the host D= ingested Dose
  8. 8.  Highlighted the presence of cryptosporidium oocysts in the surface and ground water of the coastal city of Cayes.  The watershed is divided by 3 distinct types of Aquifers: Alluvial unconfined underground, karastic and cracked and segmented carbonate.  Water samples were taken from 15 sites in September, November and December 2007, i.e at the end of rainy season and at the beginning of the main dry season. 6 sites were found to be positive for cryptosporidium oocysyts per 100L and elution method used . 9 oocysts/ 100L were obtained from water samples from public water supply service of Cayes.
  9. 9. A risk factor is an element belonging to an individual or originating from an environment liable to cause an illness, trauma or another negative impact on the development of human organism. The exposure of consumer to contaminated water is a major health risk factor. There is no control for quality of the water of the water distributed by public services. Urban areas lack basic services for the collection and treatment of wastewater and solid wastes and the removal of excreta. Chlorination is the only method used to treat raw water but it is ineffective in inactivating oocysts.
  10. 10. Conclusion: Risk assessment is not a goal but there is an decision making for risk management of oocyst hazards and risks for human health.

×